Organophilic clays

There are three general approaches to the synthesis of polymer-clay nanocomposites. In the first approach, a monomer or precursor is mixed with organophilic clay and followed by polymerization. This in situ polymerization technique was first developed by the... 

The second method of nanocomposite synthesis involves dissolving a polymer in a solvent, mixing with organophilic clay, and then removing the solvent [14,46-48]. Some... 

An oil-based drilling mud can be viscosified with maleated ethylene-propylene elastomers [919]. The elastomers are ethylene-propylene copolymers or ethylene-propylene-diene terpolymers. The maleated elastomers are far more effective oil mud viscosifiers than the organophilic clays used. On the other hand, specific organophilic clays can provide a drilling fluid composition less sensitive to high temperatures [491]. 

A fluid loss additive for hard brine environments has been developed [1685], which consists of hydrocarbon, an anionic surfactant, an alcohol, a sulfonated asphalt, a biopolymer, and optionally an organophilic clay, a copolymer of N-vinyl-2-pyrrolidone and sodium-2-acrylamido-2-methylpropane sulfonate. Methylene-bis-acrylamide can be used as a crosslinker [1398]. Crosslinking imparts thermal stability and resistance to alkaline hydrolysis. 

D. Dino and J. Thompson. Organophilic clay additives and oil well drilling fluids with less temperature dependent rheological properties containing said additives. Patent EP 1138740A, 2001. 

Montgomery DM, Sollars CJ, Sheriff TS, Perry R (1988) Organophilic clays for the successful stabilisation/solidification of problematic organic wastes. Environ Technol Lett 9 1403... 

Polymer-clay nanocomposites (PCN) are a class of hybrid materials composed of organic polymer matrices and organophilic clay fillers, introduced in late 1980s by the researchers of Toyota (Kawasumi, 2004). They observed an increase in mechanical and thermal properties of nylons with the addition of a small amount of nano-sized clays. This new and emerging class of pol miers has found several applications in the food and non-food sectors, such as in constmction, automobiles, aerospace, military, electronics, food packaging and coatings, because of its superior mechanical strength, heat and flame resistance and improved barrier properties (Ray et al., 2006). 

The presence of an organophilic clay increases the catalyst activity (10). Suitable clays include montmorillonite, hectorite, mica, etc. For example, Lucentite is a trioctylmonomethylammonium salt-treated synthetic hectorite. The clays are modified with quaternary ammonium compounds. The clays are heat treated prior to their use in the polymerization process. Further, the incorporated clay can improve the performance of the UHMWPE or function as filler. 

Tatum, J.P. Organophilic Clays for Low-Toxicity Drilling Fluids in Chemicals in the Oil Industry, Ogden, P.H. (Ed.), Royal Society of Chemistry London, 1988, pp. 31-36. 

Use Paper debonders, dye retarders, organophilic clays, antistatic agents, car-wash rinse aids, sugar clarification, fabric softeners, creme rinses. A high performance cationic quaternary fabric softener for retail, industrial, laundry, textile, and paper softener applications. 

Winterburn, G. (1988) Cooperative Test Results of Apparent Viscosity Determination at Low Shear Rates using the Constant Pressure Viscometer, NLGI Spokesman LII (8), 365-372. PoweU, T. W. (1982) Activators for Organophilic Clays in Lubricating Greases, NLGI Spokesman XLVI (8) 269-277. 

Hasegawa, N., Okamoto, H., and Usuki, A., Preparation and properties of ethylene propylene rubber (EPR)-clay nanocomposites based on maleic anhydride-modifled EPR and organophilic clay, J. Appl. Polym. ScL, 93, 758-764 (2004). 

Organophilic clays can also be homogeneously dispersed in coatings, giving them improved corrosion resistance, thermal stability, and barrier properties (decreased permeability toward water and oxygen). If the organic modifier of the clay is a dye, improved color stability against, e.g., UV irradiation, is obtained. ... 

Quite a lot of studies have dealt with the use of organoclays in emulsion polymerization. In most of these studies, the organoclay is dispersed in water and the polymerization proceeds as in conventional emulsion polymerization by monomer diffusion from the droplets to the organophilic clay surface, where propagation of polymer chains takes place. However, in a few examples, the organoclay is dispersed in the monomer phase. This monomer clay suspension is next emulsified (sometimes with the aid of ultrasound to help dispersion and promote clay exfoliation) and the resulting droplets are polymerized [262-267], The latter processes look closer to suspension or miniemulsion (depending on the nature of the initiator) than emulsion polymerization and will not be discussed further. 

Hwang, I Liu, H., 2002. Influence of organophilic clay on the morphology, plasticizer-maintaining ability, dimensional stability, and electrochemical properties of gel polyacrylonitrile (PAN) nanocomposite electrolytes. Macromolecules 35,7314-7319. 

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